Kazuto Tsuruoka began his professional baseball career in 1939 with the Nankai club of the Japanese Professional Baseball League. Tsuruoka hit .275/.403/.470 and led the JPBL with 10 homers, an impressive feat for a rookie. Kazuto then missed 6 years of his prime as he was drafted into the Imperial Army and served his country during World War II. He returned to the diamond in 1946 with Nankai, now called Kinki Great Ring. He batted .314/.422/.446, not missing a beat and leading the league with 95 RBI in 104 games. He stole 32 bases in 40 tries as well and was named MVP. He also became manager that year and managed his team to the title. In 1947 Tsuruoka hit .279/.390/.411 and led the JPBL with 79 walks, his third different category led in in his first three seasons. At age 31-32, he batted .305/.399/.434 and stole 23 bases in 27 attempts, managed his team (now called the Nankai Hawks) to another pennant and was named MVP for the second time, the third player to be so honored. In 1949 the third baseman batted .289/.380/.473 with a career-best 17 homers. The 4th-place finish that year would be the worst by a Tsuruoka-managed team for 18 years as they never finished below second again until 1967.

1950 saw the introduction of the two-league system in Japan and Kazuto's Hawks finished second in the Pacific League as he hit .286/.379/.471. A year later the Hawks began a run of three straight PL titles though they lost the Japan Series each time. In 1951 Tsuruoka made the first All-Star team, won his third MVP award (the first man in Japan to win it that many times) and hit .311/.363/.396 while managing his club to the title. Kazuto was again an All-Star in 1952 as he hit .279/.350/.426. It was his final year as a player - his career statistics were .295/.390/.439.

After 1952 Tsuruoka became Nankai's manager full-time. He led them to pennants again in 1953, 1955, 1959, 1961 and 1964-1966. His club only won the Japan Series twice, in 1959 and 1964. On the latter occasion, Kazuto pulled the risky move of starting Joe Stanka the final two games, but the move paid off, as he threw shutouts both times. Tsuruoka was inducted into Japan's Baseball Hall of Fame in 1965. He helped set up Japan's farm system and took an active role, personally scouting Katsuya Nomura, who would go on to be Nankai's best player and talking Masanori Murakami out of returning to Major League Baseball. He was highly respected by his players, including foreign players, often known for being critical of Japanese managerial tactics and style.

Overall Tusuruoka's clubs won 11 pennants and went 1,773-1,140-81 in the regular season. No manager in the history of Nippon Pro Baseball ever won more games.

Tsuruoka is famous for saying "there is money to be made on this field."